| 摘要 |
A press-forming method includes: a step of forming a first cup-shaped workpiece (B); a step of moving an axial pressing punch (13) relatively to a die (15) to abut on a cup opening end (B21) of a cup sidewall portion (B2), and while constraining the cup opening end (B21), moving a second-stage forming punch (11) relatively to the die (15) to insert the second-stage forming punch (11) into a second die hole portion (155), and pushing a part of the first cup-shaped workpiece into the second die hole portion (155) through a second die shoulder portion (154), to thereby reduce the cup sidewall portion (B2) in diameter and thicken the cup sidewall portion (B2); and a step of, in a state of the constraint of the cup opening end (B21) by the axial pressing punch (13) being released, moving the second-stage forming punch (11) relatively to the die (15) and further pushing the first cup-shaped workpiece deeper in the second die hole portion (155), to thereby form a second cup-shaped workpiece smaller in diameter than the first cup-shaped workpiece. |
